Hybrid Sharks Found in Australian Waters

Scientists have discovered widespread hybridization in the wild between two shark species commonly caught in Australia's east coast shark fisheries.
(University of Queensland)

BRISBANE, Australia – Scientists have discovered the world's first hybrid sharks in Australian waters, with multiple generations of the new creature found along the nation's east coast.

Scientists say the discovery of interbred sharks could signal the presence of new "tropical" sharks in waters as far south as Sydney, The Australian reported.

"Wild hybrids are usually hard to find, so detecting hybrids and their offspring is extraordinary," said Jennifer Ovenden from the Queensland Department of Primary Industries and Fisheries.

Fifty-seven of the marine animals were found along a 1,243-mile (2,000-km) stretch between northern New South Wales and far north Queensland, with Ovenden calling the discovery "unprecedented."

The new shark is a hybrid of the genetically distinct Australian blacktip, whose range extends north from Brisbane, and the larger common blacktip found in southeastern coastal waters.

The scientists say interbreeding between the two shark species is a sign the animals are adapting to climate change and they also warn that hybridization could make the sharks stronger.

"Hybridization could enable the sharks to adapt to environmental change as the smaller Australian blacktip currently favors tropical waters in the north while the larger common blacktip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline," Ovenden said.

University of Queensland research scientist Jess Morgan said hybridization was common in plants and relatively common among fish because of their external fertilization. "They just release their eggs and sperm into the water column," she said.

"[But] sharks physically mate, which is usually a good way to make sure you don't hybridize with the wrong species."